This disclosure relates to nested cables and to retractable cord reels and more specifically to nested cable and retractable cord reel assemblies for use with laptop computers and other electronic devices.
Internal rechargeable batteries power portable electronic devices such as laptop computers. Laptop computers are highly desirable due to their portability, which is directly related to their size and weight. Even though breakthroughs in computer technology have enabled manufacturers to miniaturize nearly all the computer components, advances in battery technology have been slow, resulting in little change in the size and weight of the batteries.
The batteries in a typical laptop will power the computer for only a few hours, which is inadequate for a normal businessperson. Manufacturers prefer smaller batteries because it allows them to market a smaller, more desirable product, but power capacity (battery life) is sacrificed. As a result, laptop users carry their battery charger or electrical adapter with them to meetings or wherever else they travel, and connect the laptop to high voltage power whenever possible. Because of their dependence on computers, businesspersons cannot afford for their batteries to ever run out.
Business people commonly bring their laptops everywhere they go during the workday (meetings, etc.), as well as home at night and on trips. This means they also bring the electrical adapter for the laptop everywhere they go. Laptop manufacturers have been very innovative in improving the portability of the laptops by adding such features as built-in or foldout mice. But little effort has been allotted to improving the portability of the electrical adapter that is taken along everywhere the laptop travels.
Typical electrical adapters are a rectangular box about 2.5xe2x80x3xc3x974xe2x80x3xc3x971.25xe2x80x3 high. It includes two cables usually about 6 feet long. one for high voltage power (extending from a wall socket to the adapter) and the other for low voltage power (which extends from the adapter to the laptop). When a person moves from an office to a conference room, he will simply fold up the laptop, but then must unplug the adapter and manually (sometimes randomly) coil the cord around his hand or around the adapter. Sometimes the cords are not coiled at all and simply dragged behind on the floor! If a coiled cord is placed on a table or in a brief case, it will begin to uncoil as soon as it is let go. The lack of portability of a electrical adapter is very much out of sync with the excellent portability of the devices they power.
Other electric devices also have problems with storage of power cords, particularly where two cords are attached to the same device. A sewing machine, for example, often has two cords extending from the foot pedal. House current is delivered to the pedal from one cord, regulated by a control device and the action of the pedal, then delivered to the machine by a second cord. Storage of the cords and foot pedal can be cumbersome. Even when a cord reel is used for one cord, the second cord must be stuffed in a separate compartment, stored in a separate reel or clumsily wrapped around the foot pedal for storage.
These and other problems are solved by the nested cables and retractable cord reel assembly of the invention. A retractable cord reel assembly is described including a housing, a spool rotatably mounted in the housing, a first cable and a second cable, each at least partly carried by the spool, and means for releasably coupling the first cable to the second cable when the first and second cables are co-wound together onto and off of the spool. Preferably, the releasable coupling of the cables includes nesting the first and second cables together. One element for nesting of the cables includes providing one of the cables with a longitudinal cavity so that the other cable is nested into the cavity when the cables are wound together. As exemplified in the specific embodiments below, many modifications may be made for particular applications.
One particular embodiment comprises a nested cable and cord reel assembly designed for the electrical adapter for laptop computers and the cables attached to it. The assembly comprises a housing; a spool mounted for rotation in the housing; an electrical component, such as an electrical adapter, carried by the spool: a high voltage power cable having a first end connected to the electrical adapter, the high voltage power cable being windable onto and off of the spool, the high voltage cable having at least one longitudinal cavity; and a low voltage power cable having a first end connected to the electrical adapter, the low voltage cable being windable onto and off of the spool, the low voltage cable being releasably nested in the cavity of the high voltage cable when the two cables are co-wound together on said spool. The free end of the high voltage cable has a plug for connection to a standard electrical outlet. The free end of the low voltage cable has a plug or other connector adapted for connection to an electronic device, such as a laptop computer. The housing may include pocket(s) or chamber(s) for internally storing the plugs or connectors.
The invention is also useful for other electrical devices, such as a sewing machine. A nested cable and cord reel assembly is suitable to store both the cord delivering power from the house current and the cord delivering the regulated power to the sewing machine with the cords nested together. The cord reel is optionally designed to fit inside the foot pedal, which provides a convenient storage location. When it is desirable to store the sewing machine for later use, both cables are wound together into the cord reel assembly that also houses the power regulator in the pedal, providing compact and convenient storage of both cables inside the foot pedal.
In its retracted state, the high voltage and low voltage plugs are inside the cord reel housing or against the side of the housing, and are easily accessible to the user. The user pulls either the high or low voltage cable to extract the desired length of cable. Since both cables are nested together when wound on the spool, approximately equal lengths of each cable are dispensed from the cord reel regardless of which cable is pulled. All or part of the cable stowed in the cord reel may be extracted.
After use, the cord is retracted into the cord reel for neat storage and portability. Many of known methods can be used to retract the cable. A spring may be incorporated to bias the spool in the cord retracting direction, and a ratchet can be used to hold the cables in the extended position until retraction is desired. A motor or hand crank can also be used to retract the cables.
In the consumer market where cost is a major consideration, the cord can be manually retracted by turning the electrical housing while holding the cord reel housing. Since the spool is attached to the electrical housing, turning the electrical housing causes the spool to rotate and the cables to retract.